<PAGE>
                                                                    EXHIBIT 10.1
                               BANK OF TEXAS, N.A.
                          5956 Sherry Lane, Suite 1100
                               Dallas, Texas 75225




August 7, 2002



TOREADOR RESOURCES CORPORATION
TOREADOR EXPLORATION & PRODUCTION INC.
TOREADOR ACQUISITION CORPORATION
TORMIN, INC.
4809 Cole Avenue, Suite 108
Dallas, Texas 75205

         Re:      Third Amendment to Loan Agreement

Ladies and Gentlemen:

         This letter (this "Amendment") amends the loan agreement dated February
16, 2001, among TOREADOR RESOURCES CORPORATION, a Delaware corporation, TOREADOR
EXPLORATION & PRODUCTION INC., a Texas corporation, TOREADOR ACQUISITION
CORPORATION, a Delaware corporation, and TORMIN, INC., a Delaware corporation
(collectively "Borrowers"), and BANK OF TEXAS, NATIONAL ASSOCIATION ("Bank"), a
national banking association, as amended by the First Amendment dated November
8, 2001, and a Second Amendment dated May 9, 2002 (the "Loan Agreement").
Capitalized terms below have the meanings assigned in the Loan Agreement.

         1. Borrowing Base, Tranches, and Rates. (a) Effective as of the date of
this Amendment, Bank has set the Borrowing Base at $21,850,000.00, and Bank has
set the MCR at $150,000 per month, until reset by Bank in connection with the
next redetermination of the Borrowing Base. The next scheduled redetermination
of the Borrowing Base will be November 1, 2002. The amount of Tranche A as of
the date of this Amendment is $20,000,000.00.

                  (b) The first three sentences of Subsection (ii) of Section
1(a) of the Loan Agreement are amended to modify the interest rates and thus to
read as follows:

                           "(ii) Until Tranche B is paid in full, all amounts
         owed on the Revolving


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TOREADOR RESOURCES CORPORATION, et al
August 7, 2002
Page 2 of 6


         Note shall bear interest from the date advanced until paid or until
         default or maturity at a fluctuating rate equal to the sum of the
         Stated Rate, plus one percent (1.0%), but subject to the default rate
         set forth in the Revolving Note. After Tranche B is paid in full, all
         amounts owed on the Revolving Loan shall bear interest from the date
         advanced until paid or until default or maturity at the rates elected
         by Borrowers from the following options under the terms of the
         Revolving Note: (i) the difference between the Stated Rate less the
         Applicable Margin, or (ii) the sum of the LIBOR Rate plus the LIBOR
         Spread. The Applicable Margin and the LIBOR Spread will vary as set
         forth below based on the ratio, expressed as a percentage, of (i) the
         sum of the average principal balance owing on the Revolving Note for
         the prior quarter, plus the face amount of all outstanding Letters of
         Credit, to (ii) the then-current Borrowing Base:

<Table>
<Caption>
                  % of Borrowing Base              Applicable Margin   LIBOR Spread
                  -----------------------------------------------------------------
<S>                                                <C>                 <C>
                  Greater than or equal to 85%           0.25%            2.75%
                  Between 75% and 85% inclusive          1.00%            2.00%
                  Less than 75%                          1.25%            1.75% . . . ."
</Table>

                  (c) Subsection (b) of Section 1 of the Loan Agreement is
amended to change the Borrowing Base and to extend the due date for Tranche B
and thus to read as follows:

                           "(b) Subject to the terms and conditions of the Loan
         Agreement, Borrowers may borrow, repay, and reborrow on a revolving
         basis from time to time during the period commencing on the date hereof
         and continuing through 11:00 a.m. (Dallas, Texas time) on February 16,
         2006 (the "Termination Date"), such amounts as Borrowers may request
         under the Revolving Loan; provided, however, the total principal amount
         outstanding at any time shall not exceed the lesser of (i) the
         aggregate sums permitted under the Borrowing Base, which is set at
         $21,850,000.00 as of the date of this Amendment, (ii) after November 1,
         2002, the aggregate sums permitted under Tranche A, or (iii)
         $75,000,000. Notwithstanding any provision in the Loan Agreement or the
         Revolving Note to the contrary, all amounts outstanding on Tranche B
         must be paid in full on or before November 1, 2002; and all sums
         advanced under the Revolving Loan, together with all accrued but unpaid
         interest thereon, shall be due and payable in full on the Termination
         Date."

                  (d) Notwithstanding any provisions to the contrary in the Loan
Agreement or the Revolving Note, until Tranche B is paid in full, all amounts
owed on the Revolving Note shall bear interest from the date advanced until paid
or until default or maturity at a fluctuating rate equal to the sum of the
Stated Rate, plus one percent (1.0%), but subject to the default rate set forth
in the Revolving Note.



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TOREADOR RESOURCES CORPORATION, et al
August 7, 2002
Page 3 of 6


         2. Letter of Credit Fees. The last sentence of Subsection (d) of
Section 1 of the Loan Agreement is amended to change the fees for Letters of
Credit and thus to read as follows:

                  "Borrowers agree to pay to Bank a Letter of Credit fee equal
         to (i) $500 issuing fee per Letter of Credit, due at issuance, plus
         (ii) until Tranche B is paid in full, three and three quarters percent
         (3.75%) per annum, or plus (iii) after Tranche B is paid in full, the
         percentages per annum shown below, calculated on the aggregated stated
         amount of each Letter of Credit for the stated duration thereof
         (computed on the basis of actual days elapsed as of each year consisted
         of 360 days), payable quarterly in arrears on the last day of each
         calendar quarter. The annual Letter of Credit fee will vary as set
         forth below based on the ratio, expressed as a percentage, of (i) the
         sum of the average principal balance owing on the Revolving Note for
         the prior quarter, plus the face amount of all outstanding Letters of
         Credit, to (ii) the then-current Borrowing Base:

<Table>
<Caption>
                  % of Borrowing Base                         Letter of Credit Fee
                  ----------------------------------------------------------------
<S>                                                           <C>
                  Greater than or equal to 85%                      2.75%
                  Between 75% and 85% inclusive                     2.00%
                  Less than 75%                                     1.75%"
</Table>

         3. Distributions to Madison Oil Company. Subsection (k) of Section 6 of
the Loan Agreement is amended to restrict distributions to Madison Oil Company
and thus to read as follows:

                  "(k) Not make any loans, advances, dividends, or other
         distributions to any party, including without limitation, shareholders,
         officers, directors, subsidiaries, and affiliates, and any profit
         sharing or retirement plan, except so long as there is not a default
         under this Loan Agreement or any other Loan Documents, (i) Borrowers
         may distribute to their shareholders an amount not to exceed $100,000
         in the aggregate, and (ii) Borrowers may distribute amounts to Madison
         Oil Company or its subsidiaries only with Bank's prior written consent;
         and not purchase, acquire, redeem, or retire any stock of Borrowers;
         and not permit any transaction or contract with any affiliates or
         related parties, except at arms length and on market terms."

         4. Fees. In connection with this Amendment and the extension of Tranche
B, Borrowers agree to pay to Bank an amendment fee in the amount of $75,000.00.
All fees are non-refundable and earned by Bank upon execution of this Amendment.

         5. Collateral. (a) As security for the Notes, Borrowers previously
executed the Security Documents. Borrowers ratify and confirm the Security
Documents, acknowledge that they are valid, subsisting, and binding, and agree
that the Security Documents secure payment of the Notes and Loans.




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TOREADOR RESOURCES CORPORATION, et al
August 7, 2002
Page 4 of 6


                  (b) As additional security for the Notes, Toreador Exploration
& Production Inc. will execute and deliver a Deed of Trust and Security
Agreement in Proper Form, covering oil and gas properties located in Meade
County, Kansas. This additional deed of trust will constitute one of the
"Security Documents" as defined in the Loan Agreement.

         6. Conditions Precedent. (a) The obligation of Bank to make any further
advance on the Revolving Loan is subject to Borrower's satisfaction, in Bank's
sole discretion, of the following conditions precedent:

                           (1) the negotiation, execution, and delivery of Loan
Documents in Proper Form, including, but not limited to, the following:

                                    (i) this Amendment; and

                                    (ii) the Kansas Deed of Trust.

                           (2) satisfactory evidence that Bank holds perfected
liens and security interests in all collateral for the Loans, subject to no
other liens or security interests.

                           (3) there being no order or injunction or other
pending or threatened litigation in which there is a reasonable possibility, in
Bank's judgment, of a decision which could materially adversely affect the
ability of Borrowers to perform under the Loan Documents.

                           (4) Bank shall have completed and approved a review
of title to, and the status of the environmental condition of, Borrower's oil
and gas properties, and the results of such review shall be acceptable to Bank
in its sole discretion.

                           (5) Bank's receipt and review, with results
satisfactory to Bank and its counsel, of information regarding litigation, tax,
accounting, insurance, pension liabilities (actual or contingent), real estate
leases, material contracts, debt agreements, property ownership, and contingent
liabilities of Borrowers and any subsidiaries.

                  (b) Bank will not be obligated to make any advance on the
Loans, if, prior to the time that a loan or advance is made, (i) there has been
any material adverse change in any Borrowers' financial condition since the
most-recent financial statements furnished to Bank, (ii) any representations or
warranties made by any Borrowers in the Loan Agreement or the other Loan
Documents is untrue or incorrect as of the date of the advance or loan, (iii)
Bank has not received all Loan Documents appropriately executed by Borrowers and
all other proper parties, (iv) Bank has requested that Borrowers execute
additional loan or security documents and those documents have not yet been
properly executed, delivered, and recorded, or (v) an Event of Default has
occurred.



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TOREADOR RESOURCES CORPORATION, et al
August 7, 2002
Page 5 of 6

         7. Confirmations. Borrowers hereby represent to Bank that all
representations and warranties of Borrowers set forth in Section 5 of the Loan
Agreement are true and correct as of the date of execution of this Amendment;
and that Borrowers are in compliance as of the date of execution of this
Amendment with all covenants set forth in Section 6 of the Loan Agreement, all
financial covenants set forth in Section 7 of the Loan Agreement, and all
reporting requirements set forth in Section 8 of the Loan Agreement.

         8. Validity and Defaults. The Loan Agreement, as amended, remains in
full force and effect. Borrowers acknowledge that the Loan Agreement, the Notes,
and the Security Documents are valid, subsisting, and binding upon Borrowers; no
uncured breaches or defaults exist under the Loan Agreement, as amended; and no
event has occurred or circumstance exists which, with the passing of time or
giving of notice, will constitute a default or breach under the Loan Agreement,
as amended. Borrowers ratify the Loan Agreement, as amended.

         9. Fax Provision. This Amendment and the related Loan Documents may be
executed in counterparts, and Bank is authorized to attach the signature pages
from the counterparts to copies for Bank and Borrowers and filing counterparts.
At Bank's option, this Amendment and the related Loan Documents may also be
executed by Borrowers in remote locations with signature pages faxed to Bank.
Borrowers agree that the faxed signatures are binding upon Borrowers, and
Borrowers further agree to promptly deliver the original signatures for this
Amendment and the related Loan Documents by overnight mail or expedited
delivery. It will be an Event of Default if they fail to promptly deliver all
required original signatures.

         10. Captions. Captions are for convenience only and should not be used
in interpreting this Amendment.

         11. Final Agreement. (a) In connection with the Loans, Borrowers and
Bank have executed and delivered this Amendment and the Loan Documents
(collectively the "Written Loan Agreement").

                  (b) It is the intention of Borrowers and Bank that this
paragraph be incorporated by reference into each of the Loan Documents.
Borrowers and Bank each warrant and represent that their entire agreement with
respect to the Loans is contained within the Written Loan Agreement, and that no
agreements or promises have been made by, or exist by or among, Borrowers and
Bank that are not reflected in the Written Loan Agreement.



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TOREADOR RESOURCES CORPORATION, et al
August 7, 2002
Page 6 of 6

                  (c) THE LOAN AGREEMENT, AS AMENDED, REPRESENTS THE FINAL
AGREEMENT BETWEEN THE PARTIES AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR,
CONTEMPORANEOUS, OR SUBSEQUENT ORAL AGREEMENTS OF THE PARTIES. THERE ARE NO
UNWRITTEN AGREEMENTS BETWEEN THE PARTIES.

         If the foregoing correctly sets forth your understanding of our
agreement, please sign and return one copy of this letter.

                                      Yours very truly,

                                      BANK OF TEXAS, NATIONAL ASSOCIATION


                                  By: /s/ Timothy E. Merrell
                                      -----------------------------------------
                                      Timothy E. Merrell,
                                      Senior Vice President

Agreed on this 7th day of August, 2002:

BORROWERS:

TOREADOR RESOURCES CORPORATION


By:      /s/ Douglas W. Weir
         -------------------------------------
         Douglas W. Weir, Vice President

TOREADOR EXPLORATION & PRODUCTION INC.


By:      /s/ Douglas W. Weir
         -------------------------------------
         Douglas W. Weir, Vice President

TOREADOR ACQUISITION CORPORATION


By:      /s/ Douglas W. Weir
         -------------------------------------
         Douglas W. Weir, Vice President

TORMIN, INC.


By:      /s/ Douglas W. Weir
         -------------------------------------
         Douglas W. Weir, Vice President


Exhibits:
None